The experiments in this proposal are designed to investigate the role of selective attention in the information processing decrements found in older persons. The general premise of these studies is that some of the cognitive decline seen with advancing age results from an inefficient allocation of processing capacity, that is, from a deficit in selective attention. We will investigate how efficiently young, middle aged, and elderly individuals attend (i.e., restrict their processing) to the relevant information in their sensory input, while ignoring (not processing) irrelevant or redundant information. A visual search paradigm will be used for many of these studies. We will measure the facilitative and inhibitory effects that advance information defining a portion of the stimulus array as being relevant (ie., potentially containing a target), has upon the reaction time for determining whether or not a target is actually present. Other experiments will examine how subjects learn, over extended practice, to gradually reduce the attentional demands of the search task so that the relevant target items are identified automatically.